Using a Jinja2 variable in an "%include" statement

Yes you’re right. We should mention this in the docs, where %include is documented, and in the Jinja2 section. (Sorry for that omission!).

Fortunately, Jinja2 has its own template inclusion mechanism to do what you need:

#!Jinja2

{% set inc1 = "include.flow" %}
[scheduling]
...
{% include inc1 %}